Effect of ITER blanket manufacturing process on the properties of the 316L(N)-IG steel

Austenitic stainless steel 316L(N)-IG is proposed as one of the base structural materials for the international thermonuclear experimental reactors (ITER) in-vessel components. Various fabrication techniques (hot isostatic pressing (HIP), powder metallurgy, fusion welding and casting etc.) were assessed for the high heat flux components. HIP is the most perspective option because it allows to manufacture components with complicated shape and to provide joining of heat sink and plasma facing materials, simultaneously, during the same HIP cycle. The paper deals with the results of investigations of the repeated thermal cycle effect on the 316L(N)-IG steel properties. It is shown that most significant changes of strength were observed after first heat treatment (HIP) cycle. Results of microstructure investigation and stress corrosion cracking (SCC) are also presented in the paper.